I sometimes teach computer networking to adults and I have all different levels of knowledge in the class, so my take is I have to assume the lingo and devices being taught are new to the whole class. If someone doesn't get the point in a lesson, I try to take it from another angle.
I would think that much of the same is happening on quilt shows. They have to assume a lack of knowledge in their audience to make sure they are giving useful information for all levels of education, beginner and advanced.
Diane